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New submitter nfn writes "MIT has published a new paper (abstract), along with a video of a working prototype, of what they're describing as an 'Artificial Leaf' that separates water into oxygen and hydrogen using cheap, non-exotic materials. 'The artificial leaf — a silicon solar cell with different catalytic materials bonded onto its two sides — needs no external wires or control circuits to operate. Simply placed in a container of water and exposed to sunlight, it quickly begins to generate streams of bubbles: oxygen bubbles from one side and hydrogen bubbles from the other. If placed in a container that has a barrier to separate the two sides, the two streams of bubbles can be collected and stored, and used later to deliver power: for example, by feeding them into a fuel cell that combines them once again into water while delivering an electric current.' No word on the arrival of 'Artificial Salads,' or when any of their other alchemy projects will bear artificial fruit."

Besides the debate as to whether this is a duplicate story, electrolysis has been around since the 19th century. The only thing here is that they are using solar cells to generate the power. Seems to me like saying a Reese's Peanut Butter Cup is a new discovery because they mixed chocolate with peanut butter.

This is, in fact, a revolutionary new catalyst potentially worth billions. It does the same thing as conventional electrolysis, but is more than 20 times as efficient as just sticking two wires into a bucket. When I saw Nocera present this research at the Spring ACS conference, my jaw was just about on the floor.

Here's what Wikipedia says about the efficiency of conventional electrolysis:

The energy efficiency of water electrolysis is a measure of what fraction of electrical energy used is actually contained within the hydrogen. Some of the electrical energy is converted to heat, an almost useless byproduct. Some reports quote efficiencies between 50% and 70%.

By not believing wikipedia? LOL Also note wikipedia says "some reports", not that conventional electrolysis (whatever that is) is 70% efficient.
Finally, perhaps by 20 times more inefficient, they mean that they waste 1/20 of the energy, meaning it goes from 30% loss to 1.5% loss.
Use your imagination, fool!:-)

No, one of Nocera's previous papers was posted [slashdot.org], not the one published yesterday. This one is a lot more in-depth synthetically and has much stronger characterization and shows that it actually works as a full system - the earlier paper was just a communication saying, "Look, we did this first!"

Given that project is a rehash of existing technology published several months ago, is it OK to agree with you? I RTFA, and was hoping that the prototype had gone into production. It appears that the development team is in an endless loop; maybe a business undergrad at Stanford could guide them out? The general business model using this technology was described by Poul Anderson in, "The Boat of A Million Years". It would have been nice if the team had demonstrated something a little more robust, like a

Besides, some Texans who do work for the oil companies are pushing stuff like biofuels from algae greenhouses. I wait with bated breath to see if they can create fuels straight to the pump from genetically modified algae, i.e. no refinement necessary, and I wait with whispring humblenesse to see if they make it to market without disappearing somewhere in the English Channel.

FWIW the state government is involved. I'd wager there are quite a few texas politicians that are all for developing new in-state energy sources, state infrastructure, products to export to other states, etc.

and also FWIW there have been quite a few texas politicians that have chosen extremely violent attacks to maintain their position in the petroleum market. Sorry they come from your neck of the woods; shouldn't reflect badly on you. Maybe next time you see some psychopath with rising popularity coming out of the oil families you could do us all a favour by treating him to a 'texas suicide'. It worked well for the Enron whistleblower; I think it could be more widely applied.

Yes; the (R) and (D) for the most part is just a big conspiracy to block any meaningful change. Of course you only mentioned one "side" which is no better than the other. In truth both "sides" are evil.

The real battle is between the establishment and the outsiders - people who actually have independent critical thought.

It seems to me (R) generally want to deregulate business and regulate our personal lives. The (D) generally want to regulate business and deregulate our personal lives. This is the real difference.

Those are just the talking points. The (D)s want to regulate your personal life, they just use environmentalism, egalitarianism, and "compassion" as their excuses, rather than religion and traditional morality. The (R)s want to regulate business to pick the winners.

No Worries for the Greens, The government will give a couple billion dollars to prop up yet another failing "solar" company that cannot make it without a handout.

As opposed to the trillions of dollars in 'handouts' to Saudi Arabia and the rest of the Middle East to keep the oil flowing? Or did you think we like to support backwards misogynist despots because they're just like us? (A reasonable supposition, I suppose).

Anyhow, don't we only get some trivial % of oil from the Middle East, with most of it coming from much closer (hello, Canada)?

That's like saying you don't buy electricity from the power company because of the fact that the electrons that arrive at your house aren't the same ones that left the power station.

Oil is a fungible commodity. If they stopped producing it in the Middle East, then the countries closer to them would start buying up the Canadian and South American oil we now consume, driving up the price we pay by hundreds of dollars per barrel. That's why we prop up Middle East producers.

Sure, sure, but is there any reason we should care who controls those countries? Whoever is in charge, they're going to sell that oil (or we'll see the first non-greedy government in history which would be something!), and it's not likr we're getting a special deal or anything. I don't get the rational here.

But Oil Companies pay a shit load of taxes, and the government gets its share on every gallon of gas sold. The real sad thing is that the government makes more on every gallon of gas than do the oil companies. A shit load worth. Green Companies like GE don't pay any taxes or get BILLIONS in loan guarantees only to go belly up four months later.

I'm not a big Corporation fan, in fact, I would establish a bunch of rules for corporations that would prevent them from affecting politics at all (no PAC, No Lobby,

No, they'll just wait and see if it's even practical to manufacture large scale. If it is, they'll either swoop in and buy up all the companies/patents involved or have their government lapdogs in Congress bury it under volumes of obstructive laws and regulations (you see they DO believe in govt regulation, just as long as it effects competitors but not themselves).

you see they DO believe in govt regulation, just as long as it effects competitors but not themselves

Of course big companies believe in government regulation. The more the better, since the overhead of lawyers and government regulation specialists is trivial to the Exxon's of the world but enough to put small competitors out of business. It's even better when they can throw a bunch of money around in Washington and capture regulatory agencies.

If they're really concerned about this, they should torrent out the research and other documentation. I'm not worried though. Even if the whole thing were to "disappear" over night, at least people know it's now possible to do. That in of itself is a motivator to re-invent the stuff knowing it has been done before.

I think all this hydrogen tech is very dangerous, we will start burning hydrogen and more of it will leak and escape from the earth since it is so light and before too long we will run out of water. Oh we will have plenty of oxygen, but the oceans will dry up and all life will die except the giant sandworms... At least we will have spice.

Not joking. This is obviously not a short-term problem, I'm wondering just how long-term of a problem it really is, and if any possible human-caused additional leakage could ever be significant compared to the natural loss rate.

I.e., does it take only a million years for the effects to be noticeable, or does it take 10 billion? If it's less than the expected habitable lifetime of the planet, then it's an interesting question.

Hydrogen is reactive. It will react with something on the way up through the atmosphere, that makes it sufficiently heavy to stick around. The problem with helium is that it is inert. It's perfectly content on its own, so it will simply float to the top of the atmosphere and exist in trace densities not economical to capture.

This is true, unfortunately there is another highly reactive oxidizer [wikipedia.org] very high up in the atmosphere that any escaping hydrogen will react with so I wouldn't be too worried about it leaving the planet entirely, but we might have other problems.

Actually, you bring up a decent point. Hydrogen is not very energy dense. This system would be great if we had a practical fusion reactor, but we don't. A much superior system would be one which takes sunlight, CO2 and water and produces a complex hydrocarbon that could then be used as fuel.

I was thinking along the lines of something that gets the energy to do this from sunlight. Actually, there are things which do so and are being used to create biofuel. It would just be nice if we could stick something like these "leaves" in a water and CO2 bath in the sun and get complex hydrocarbons. On the other hand, the methods they have for doing that already are actually pretty good.

Oh yeah, because solar stills produce hydrogen and oxygen as well as water by utilizing electricity.

The only thing they have in common is that they use the sun (although, in very different ways). The artificial leaf doesn't produce water, at all. Clean water is a byproduct of utilizing the hydrogen as a fuel (as is heat).

Nothing like a solar still.

Although we don't know a price on these devices, they are made from non-exotic (read common) materials. Even if they cost more than pocket change, the longer t

From the article: "The new device is not yet ready for commercial production, since systems to collect, store and use the gases remain to be developed."

Yeah, right. This would be in commercial production right now, if only there were compressors and hydrogen tanks.

The reason why this is not in production is obvious. The energy capturing efficiency (and hence cost effectiveness) of the solar cell is reduced by 75 %. (Then another 50 % will be lost if the hydrogen is converted back to electricity.)

The reason why this is not in production is obvious. The energy capturing efficiency (and hence cost effectiveness) of the solar cell is reduced by 75 %. (Then another 50 % will be lost if the hydrogen is converted back to electricity.)

Physical efficiency may not be a big deal here. If you are using inexpensive materials and can get the device built reasonably cheaply and it has long term stability (several largish engineering 'ifs' here) then overall energy conversion rates aren't too critical. There is lots of sunlight and lots of water so you can trade off efficiency for square footage (to some degree, it can't be terribly bad at conversion).

The devil will be in the details and as TFA states, there is a lot of engineering work to be

The reason why this is not in production is obvious. The energy capturing efficiency (and hence cost effectiveness) of the solar cell is reduced by 75 %. (Then another 50 % will be lost if the hydrogen is converted back to electricity.)

Hey, it's not like this process is in competition with some more efficient process for that sunbeam. This device would be capturing otherwise unharvested sunlight, so it's closest competition is producing Zero energy in comparison.

Things like wind and solar that have extreme peaks and valleys in their generation curve could use this (or any other means of hydrolysis) to produce a steady 24/7 stream of power. They simply need to run a small electrolysis plant and a gas compressor on the supply side, And then burn the hydrogen to run a steam turbine/generator. Yes, there is some loss of efficiency in doing it, but so what? It gives you a 24/7 smooth continuous supply.

Back in high school I used to do this with a beaker of H2O, a bit of acid to improve conductivity, a battery, and a couple of wires. Nice to know that in the succeeding 40 years or so they've improved the process so greatly by replacing the battery with a solar cell.

Good point. Forgotten "costs" like toxic crap. Curious how the over all system compares for toxic materials. I would assume it's better, and possibly by quite a bit just because of the batteries, but by how much.

The innovative bit is the cobalt catalyst. A lot of other designs use toxic electrolytes (as you mention) or expensive rare metal catalysts. This one has the advantage that all the raw materials are relatively cheap, for a solar panel design - no expensive platinum, gadolinium, etc.

Put it in sunlight and it gives off hydrogen and oxygen, in stoichiometric ratio, from the two sides.

So, if you take this thing and put it in a two-gallon zip bag with a cup of water, in a short time, you have a bomb.

Hydrogen-Oxygen explosions are no joke. This invention sounds like a way for someone to get hurt, by accident. Presumably one would like to have the fuel and oxidizer come off in disjoint, non-connected spaces.

Disclaimer: Note that any descriptions of hypothetical events are metaphorical in

Few fuels contain as little energy per unit volume as hydrogen at atmospheric pressure. Two gallons of H2 is less than the fuel in a cigarette lighter.

My high school chemistry teacher used to fill balloons with H2 and O2 at stoichiometric ratio and hold them over a bunsen burner (on a 1 meter stick). They make a large pop of course, but the effect is not much larger than when the balloon is filled with pure O2 and the only fuel is the balloon itself.

wherein [insert solar collector here (e.g. algae)] is used to output [lipids, hydrocarbons, hydrogen, or electricity], but has a net negative energy return and won't scale worth a crap even if it was energy positive.

My memory of highschool physics tells me that if one side is taking hydrogen out of water, then oxygen must be left... why doesn't that oxygen bubble up as well like the hydrogen does? Or does the split off Oxygen somehow make it to the other side?

Umm, I hate to break it to you, but all devices use more energy than they produce. The reason that oil and gas is so effective for us is that they are the result of a few million years of energy conversion, and we just leverage the equivalent of a battery that has been charged for a few million years.

The only question that matters is whether the energy is easily storable, produces a useful amount of energy and does not result in unmanageable pollution problems.

What I would like to know is if this device can produces net energy over its lifetime after the total energy to produce and maintain it is taken into account

Umm, I hate to break it to you, but all devices use more energy than they produce

Yes, but he's concerned about the payback of the already-captured energy invested to capture more, not in the solar energy captured. There's a rumor going around that solar panels take more (caputred) energy to build than they ever produce - and these are less efficient b

...let the off-gas float up a large hill through tubes, burn/redox the hydrogen for power generation, cool the exhaust, store the water at the top of the hill, let it return to the bottom of the hill at night to smooth out energy production...

The gravitational energy from pumping the water up the hill is several orders of magnitude less than the energy of separating the water into hydrogen and oxygen.

If you really want to use sunlight to pump hydro, just evaporate the water at the bottom of the hill and con

GP did not suggest "pumping the water up the hill"; instead, they suggested to let the hudrogen float up to the top of hills through tubes, then burn (still on high ground) said hydrogen, store locally the exhausts until cool enough, then let the water flow back downhill.